Water And Water Pollution

9.A sample of water boils at 101.5 °C. What is the approximate boiling point of pure water in °C?

10.Impurities in water increase its melting point and decrease its boiling point.

11.Which of the following is NOT a step in the treatment of water for drinking?

12.Name two bacterial diseases that can arise from consuming untreated water.

13.Anhydrous cobalt(II) chloride is blue and turns pink in the presence of water.

14.Anhydrous copper(II) sulfate is blue and turns white in the presence of water.

15.What is the colour of hydrated cobalt(II) chloride?

16.Which substance is used to test for water by a colour change from white to blue?

17.A sample of water boils at 101.5 °C. What can be concluded about its purity?

18.Why is distilled water used in practical chemistry instead of tap water?

19.Anhydrous cobalt(II) chloride is blue. What colour does it turn in the presence of water?

20.Which of the following are correct statements about the test for water? (Select all that apply.)

21.Match each water treatment stage with its purpose.

22.Place the following water treatment stages in the correct order from first to last.

23.Which of the following are bacterial diseases that can arise from consuming untreated water? (Select all that apply.)

24.Arrange the following steps to correctly describe how distilled water is produced:

25.A student measures the boiling point of a water sample and finds it to be 101.3 °C. Which of the following is the most likely conclusion?

26.Impurities in water decrease its melting point.

27.Match each water treatment stage with its primary purpose.

28.Arrange the following stages of water treatment in the correct order, starting with the first stage.

29.A student adds anhydrous cobalt(II) chloride to two different liquids. In liquid X, the cobalt(II) chloride turns pink. In liquid Y, it stays blue. Which of the following is correct?

30.Which of the following is the correct equation for the reaction of anhydrous cobalt(II) chloride with water?

31.A student tests a colourless liquid with anhydrous copper(II) sulfate. The solid turns blue. Which conclusion is correct?

32.In an experiment to determine the purity of a water sample, a student measures its boiling point as 101.2 °C. Which of the following is the best conclusion?

33.Which of the following are purposes of the stages in water treatment? (Select all that apply.)

34.Anhydrous cobalt(II) chloride turns from blue to pink in the presence of water.

35.Place the following stages of water treatment in the correct order, starting with the first stage.

36.A student adds a few drops of a liquid to anhydrous cobalt(II) chloride paper. The paper remains blue. The student then adds the same liquid to anhydrous copper(II) sulfate, which remains white. Which statement is correct?

37.What is the colour of anhydrous cobalt(II) chloride?

38.Which of the following is the correct colour change when anhydrous cobalt(II) chloride reacts with water?

39.A student adds a colourless liquid to anhydrous copper(II) sulfate. The solid remains white. What can be concluded?

40.Impurities in water increase its melting point.

41.Which of the following are correct statements about the test for water using anhydrous copper(II) sulfate? (Select all that apply.)

42.A student measures the boiling point of a sample of water and finds it to be 102.3 °C. What does this indicate about the sample?

43.Distilled water contains fewer dissolved impurities than tap water.

44.Match each stage of water treatment with its primary purpose.

45.A student heats a sample of impure water and records its boiling point as 102.4 °C. Pure water boils at 100.0 °C. What is the increase in boiling point in °C?

46.State one reason why distilled water is used in chemistry experiments instead of tap water.

47.A sample of water is found to have a boiling point of 100.9 °C. The boiling point of pure water is 100.0 °C. The increase is due to dissolved salt. If each gram of salt per litre raises the boiling point by 0.5 °C, what is the concentration of salt in g/L?

48.A sample of water is found to have a boiling point of 101.2 °C. What is the increase in boiling point compared to pure water?

49.Complete the word equation for the reaction of anhydrous cobalt(II) chloride with water.

50.The melting point of a water sample is measured as -2.5 °C. Pure water melts at 0 °C. What is the decrease in melting point?

51.Complete the sentence about the purpose of chlorination in water treatment.

52.Describe how you would determine whether a sample of water is pure using melting point data.

53.Describe how you would determine whether a sample of water is pure using boiling point data.

54.Explain why distilled water is preferred over tap water when carrying out a chemical test that involves a colour change.

55.A student heats a sample of impure water and records its boiling point as 102.4 °C. Pure water boils at 100.0 °C. What is the increase in boiling point in °C?

56.A sample of water is found to have a boiling point of 100.9 °C. The boiling point of pure water is 100.0 °C. The increase is due to dissolved salt. If each gram of salt per litre raises the boiling point by 0.5 °C, what is the concentration of salt in g/L?

57.A sample of water is found to have a boiling point of 101.2 °C. What is the increase in boiling point compared to pure water?

58.The melting point of a water sample is measured as -2.5 °C. Pure water melts at 0 °C. What is the decrease in melting point?